1. Field of the Invention
The present invention relates to an information processing apparatus and control method, more particularly to an information processing apparatus and control method capable of changing the number of revolution of a blower and a processing rate of a processor in response to a noise caused by surroundings.
2. Description of the Related Art
Conventionally, there has been proposed an information processing apparatus having a blower rotated at a certain rotational speed to cool inside the apparatus with a power switch on. In this case, the noise of blower remains unchanged, but in the case where the surrounding of the information processing apparatus is quiet, the blower noise offends our ears.
Japanese Patent Laid-open Publication No. Hei8-65612 has disclosed a xe2x80x9cprojectorxe2x80x9d as shown in FIG. 2. Referring to FIG. 2 showing the projector, a microphone 4 is mounted on an outer housing 1 of the projector to collect a noise of surroundings and feed a signal from the microphone 4 to a sound detector 5, calculating the sound volume of noise from the signal. The sound volume is then supplied to a discriminator 7 through a controller 10. The discriminator 7 reads out a reference value of noise level from a memory 6 where the values are previously stored therein, to compare the sound volume with the noise level read out from the memory. The discriminator 7 also outputs command data so that the blower rotates under a state of the noise level suitable for the calculated sound volume. The command data is transferred from the controller 10 to a suction fan driving unit 8 for driving a blower 2 and an exhaust fan driving unit 9 for driving a blower 3, and both the driving units 8, 9 rotate the blowers 2, 3, respectively. Therefore, the blowers 2, 3 of the projector are rotated suitably under the noise of surroundings. Because of this, in the case where the noise of surroundings is relatively low, the projector is cooled with low revolution of the blowers, while the noise thereof is relatively high, it is cooled with high revolution of the blowers. As a result, the noise in the low revolution does not offend our ears where the projector is placed on relatively quiet surroundings. However, the airflow is small and cooling effect is low in rotating the blowers in low revolution, conversely, it is large and high in high revolution.
It is therefore an object of the present invention to provide an information processing apparatus and control method capable of controlling the blower rotational speed processing rate and heat output of the processor in response to noise of surroundings, thereby enhancing reliability of the apparatus.
According to an aspect of the present invention, there is provided an information processing apparatus including: a power supply for supplying a power; a sound collector for collecting a noise of surroundings, i.e. ambient sound level to output a sound volume; a sound volume recognizer that calculates a measuring value from the sound volume, compares the measuring value with a reference value and outputs a revolution or rotational speed control signal and a sound level signal; a voltage controller for controlling the power supplied from the power supply in response to the rotational speed control signal; a blower having a fan rotated with the power supplied from the power source to cool inside the apparatus; an operation setting unit for producing and outputting an operational signal indicative of a processing rate from the sound level signal; and a central processing unit changed the processing rate in accordance with the operational signal to perform operation of the unit.
The reference value compared with the measuring value may be a predetermined value in a range of operating the apparatus.
The sound volume recognizer may calculate the measuring value from the sound volume to compare the measuring value with the reference value and output a low revolution control signal to the voltage controller and a low sound level signal to the operation setting unit when the measuring value is smaller than the reference value.
The sound volume recognizer may calculate the measuring value from the sound volume to compare the measuring value with the reference value and output a high revolution control signal to the voltage controller and a high sound level signal to the operation setting unit when the measuring value is larger than the reference value.
The voltage controller may transform the power from the power source to supply a high electric power to the blower for high rotational speed operation when the rotational speed control signal is a high revolution control signal, and transform the power from the power source to supply a low electric power to the blower for low rotational speed operation when the revolution control signal is a low revolution control signal.
The operation setting unit may output a high rate operational signal to the central processing unit when the sound level signal is a high sound level signal and output a low rate operational signal to the central processing unit when the sound level signal is a low sound level signal.
The central processing unit may perform a processing operation under a high rate clock frequency when the operational signal is a high rate operational signal, perform the processing operation under a low rate clock frequency when the operational signal is a low rate operational signal, and make the apparatus to be set to a standby state and restrain the calorific value caused by the apparatus.
According to a second aspect of the present invention, there is provided a control method for an information processing apparatus for measuring ambient sound volume, changing the rotational speed of a blower for cooling inside the apparatus, and changing a processing rate to control heat produced from the apparatus, comprising the steps of: (a) collecting ambient noise, and producing a sound volume; (b) calculating a measuring value from the sound volume to compare the measuring value with a reference value and producing a rotational speed control signal and a sound level signal; (c) controlling a power in response to the rotational speed control signal; (d) rotating a fan in a blower with the power to cool inside the apparatus; (e) producing an operational signal indicative of a processing rate in response to the sound level signal; and (f) changing the processing rate in accordance with the operational signal to perform operation of a central processing unit.